Heat the oil in a large pan, add the onions and dry mushrooms and fry over a medium heat until onions are lightly colored.
Add the garlic, chili powder, cumin, coriander and ginger and cook gently for 5 minutes, stirring occasionally. If necessary, add a little water.
Add the beef and cook, stirring, until brown all over.
Add the tomato purée, salt and just enough water to cover the meat; stir well and bring to a boil.
Add the potatoes and fresh chilies. Then cover, and simmer for about 1 hour, or until the meat is tender and the potatoes cooked through. You may need to add more hot water from time to time, but your aim is to have a dry-ish curry.
Notes
Serve your curry dish a crusty loaf of French bread.